A proven diagnosis of CF as evidenced by a positive sweat test (sweat sodium or chloride >60 mEq/L by quantitative pilocarpine iontophoresis), or genotype and clinical symptoms consistent with the diagnosis of CF

Able to perform reproducible spirometry maneuvers at Visit 1 in accordance with the American Thoracic Society (coefficient of variation for three FEV1 maneuvers <=0.2)

FVC <40% predicted for height, age and sex at Visit 1

On a stable regimen of chest physiotherapy (CPT) begun at least 7 days prior to Visit 1

Able to complete the 6-minute walk test at Visit 1

Exclusion Criteria:

Use of an investigational drug or device within 28 days prior to Visit 1

Experiencing an episode of severe acute respiratory failure, as determined by the investigator

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00311506